Relay



Aug. 14, 1928. 1,680,708 r o. c. TRAVER RELAY qriginal Filed Nov.24. 1926 I ventor: O|Lver- C .Trave r.

Hts Attorney.

Patented Aug. 14, 1928.

UNITED STATES PATENT OFFICE.

omvim C. TBA'VEB, OI- SCHENECTADY, NEW YORK, ASSIGNOR 'IO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

RELAY.

Original application filed November 24, 1926, Serial lIo. 150,806. Divided and this application filed April 30, 1927. Serial No. 188,008.

from the following descri tion when con-.

sidered in connection with t e'accompanying drawing, and its scope will be pointed out in .1 the appended claims.

In the accompanying drawin Fig. 1 illus-.

trates diagrammatlca y a sync omzing device embodying my invention, and Fig.2 is a vector diagram explanatory of the operai'ion of the synchronizing device shown in ig. 1'. v For purposes of illustration, I have shown in Fig. 1 of the accompanying drawing an embodiment of my invention as applied to a synchronizing device for a three phase alternating current electric system comprising an alternating current circuit, such as a bus 3 to which may be connected, by any suitable switching means 4, another alternating current circuit 5 shown as comprising an alternator 6. The switching means 4 may be of the latched closed t pe, and, as shown comprises a closing coil whose circuit is arranged to be energized from a control bus 8 through the contacts 9 of a controlrelay 10. Included in the circuit of the control relay 10 for o suing the circuit thereof upon closure of t e switching means 4, is an auxiliary switch 11 associated with the switching means and -arranged to be closed when the switching means is open, and vice versa.

.For controlling the control relay 10 andthrough this relay the switching -means 4, so as to .start'the closingo ration thereof in time toeflect closure w en the electroniotiveforces of the circuits 3 and 5 are substantially alike in dphase and frequency, there may be provi ed as set forth in my aforesaid application, electroresponsive means controlled in accordance w1th the phase vdiil'erence and the difference between the frequencies of the electromotive forces of the circuits 3 -and 5 so that the closing operation of the switching means 4 is started only at a redetermined phase difference when the requency difference is less than a predetermined value. The electroresponsive means shown comprises a lurality of difierential relays 12 and 120, t e latter of which represents an embodiment of my present invention. These relays are arranged respectively to control a plurality of circuit controlling members, suchas movable con tacts 13 and 14 which, in order to start the closing operation of the switching means,

.must simultaneously be in predetermined positions. For this purpose, the circuit controlling members 13 and 14 are arranged to control contacts 15 and 16 respectively,

which are arranged .in series in a control circuit including the control relay 10, an auxiliary relay 17 and the auxiliary switch 11 and firranged to be energized from the control The circuit controlling member 13 is arranged to be controlled in accordance with the difference between the vector sum of and the vector diiierence between the electromotive forces of the circuits 3 and 5 and to tend to move to circuit controlling or switch closing osition during a predetermined range of p ase difli'erence, which may include phase By suitably adjustin the motor elements a 19 and 20, either of t ese elements can be arranged to predominate over the other throughout a predetermined range. in the phase difference of the electromotive forces of the circuits 3 and 5 and the other element to predomina'tethroughout the remainder of the phase difference range. For example, referring to Fig. 2 in which E is taken as a stationary vector representing the .electromotive force of the bus 3 in a position considered as the in-phas'e conditiongthe motor element 19 may be arranged to predominate over the'm'otor element 20 when the hase 4 difierence is anywhere within a pre etershown,

mined range, herein shown as including phase coinc dence and indicated b the angle a between the vectors e and 6,,

sent two instantaneous positions of the e ectromotiveforce e of the circuit 5 relatively to E. Thus, whenever the phasediflerence is anywhere within the range represented by the angle a, the motor element 19 overcomes the restraint of the motor element 20 and tends to move the disk 18 in circuit closing direction. .Outside of this range or in the angle (360a), the motor element 20 overcomes the restraint of the motor element 19 and tends to move the disk 18 in the opposite direction.

The circuit controlling member 14, as

is arranged to be controlled in accordance with the difference between the vector sum of and the vector difference between corresponding elec-tromotive forces of the circuits 3 and 5 and to be actuated substantially instantaneously on the occurrence of a predetermined phase difference near phase coincidence, such as indicated by the angle 5 between E and c within the range of phase difference indicated by the an 1e a over which circuit closing operation 0 the circuit controllin member 13 may occur. For thispurpose, the differential relay 120 which controls the circuit "controlling member 14 comprises electromagnetic torque producing means such as shaded pole motor elements 23 and 24 arranged to exert opposing torques on a movable member such as a disk 25. This disk is arranged for movement between two positions, which are determined by adjustably positioned stops 26 and 27 against whic a pin 28 on the disk abuts. The disk 25, in its movement from one position to another, is arranged to actuate the circuit controlling member 14 through a contact controlling mechanism such that, as the disk movesthrough an intermediate position, the circuit controlling member momentarily engages the contacts 16. For this purpose, the contact controlling mechanism ma comprise, as shown, a toggle having a on. a fixed nected to a ink 33 which is pivotally con- ;with corresponding electromotive purpose, the windin lin 29 which is mounted to move with the disk 25 and a link 30 which is pivotally connected to a lever 31. This lever is mounted ivot 32 and is pivotally connected to an arm or crank 34.. This crank is mounted on a fixed pivot 35 and carries the-circuit controlling member 14.

The motor element 23, as shown, comprises two windings 36 and 37 which are connected to be energized in accordance forces of the circuits 31nd 5 respectively. For this 36 and 37 may be connected to the secon anes of potential transformers 38 and 39 respectively whose rimaries are connected across correspon mg phases of the circuits 3 and 5 respectively.

w ich re retion indicated by the arrow 40. The motor element 24, as shown, also comprises two windings 41 and 42 which are connected to be energized in accordance with corresponding electromotive forces of the circuits 3 and 5 respectivel The windings 41 and '42 are so connecte and arranged as to produce an electromagnetic efiect dependent on the vector diiference of the corresponding electromotive forces. This efiect, manifested .as a torque by virtue of the shaded poles, is therefore a minimum when the phase difference of the electromotive forces is zero, and a maximum when the phase difference is 180. In the arrangement shown, the torque 'of the motor element 24 tends to turn the disk 25 in the direction indicated by the arrow 43.' By suitable adjustment of the shaded oles of the motor elements 23 and 24, the ormer can be arranged to predominate over the latter at a predetermined phase 'diflference such as indicated by the position of the electromotive force vector e, and vice versa for the position e which may be substantially 186 from 6 In order, however, to have a substantially instantaneous movement of the disk 25, the material thereof is so distributed, portions or slots 44 and 45, that when either motor element 23 or 24 predominates to element is increased and the torque of the weaker element descreased, by reason of more of the disk being presented between the poles of the strongerelement and less between the poles of the weaker ,element. In order to prevent unnecessary oscillation of the disk 25 and wear on the parts caused by such oscillation, a damping magnet'46 vma be provided.

he toggle 29, 30 is so arranged that, in the extreme positions between which the disk 25 is movable, its efiective lengths are the shortest. Then, ,as the disk 25 moves from one extreme position to an intermediate position, the toggle is moved from one side-of its dead center fl position to the dead center ppsition. The e ective length of togfile is. ereby increased to a maximum-an e circuit controlling member 14' momentarily engages the contacts 16. As the disk 25 moves from this intermediate position to its other extreme position, the toggle is moved to the other side of its dead center sition. The efiective length of the toggle 18 thereby decreased and the circuit controls ling member 14 is retracted. 1

Assuming the various parts positioned as shown in Fig. 1, and that it is desired to connect the alternator 6 to the bus 3,then as the phase diiference between the electromotive forces of the bus and the alternator comes within a predetermined range indicated by the anglea between the vectors (2, and e Fig, 2, the motor element 19 will predominate and close the contacts 13, if the frequency is below a predetermined value. If the contacts 14, 16, which close momentarily at some predetermined phase difierence 6 close before the contacts 13 and 15 have closed, the switching means .4 will not be closed.- If, however, the contacts 14, 16, close momen tarily while contacts 13, .15 are closed, the control circuit, energized from the control bus 8 and comprising in series the contacts 14, 16, the contacts 13, 15, the auxiliary relay 17, the control relay 10 and the auxiliary 'switch- 11, will be completed. This eifects the energization of the control relay 10, and

through its contacts 9, the energization of' the closing coil 7 to start the closingoperation of the switch 4. The auxiliary relay 17, when energized, closes its own circuit through its contacts 47 so that thecontrol relay 10- re mains energized until the auxiliary switch 11 opens, even though the contacts 14, 16 are closed but momentarily, While the contacts '14, 16 may be closed momentarily when the phase difference is that indicated by the vector e;,-the closing operation of the switch 4 cannot then be started, since'e is within-the range (360'a), where the. contacts 13, 15 cannot be close While I have shown and described only one embodiment of my invention, I do not desire to be limited to the exact arrangement shown and described, but seek to cover in the appended claims, all those modifications that fall within the true spirit and scope of my invention. v

What I claim as new and desire to secureby Letters Patent of the United States, is

'-1. A differential relay comprising relatively movable cooperating contacts, 'a member movable between two positions, electro-' magnetic means for moving the member arranged to exert opposing torques thereon,

and contact controlling mechanism arran ed ,i-

to be actuated on movement of the mem i! due to an unbalance ofthe torques exerted rangedto exert opposing torques thereon,

and contact controlling mechanism com rising a toggle arranged to be actuated rom one side of the dead center position to the other on an unbalance of the torquesoexerted on the member for efl'ecting a momentary. circuit closure of the contacts as the toggle is moved through the dead center position;

3. A relay comprising relatively movable -cooperating contacts, a member movable between two positions, means compris ng, an

eleotromagnet for moving the member, and

contact controlling mechanism comprising a toggle arranged to be actuated from one side 'of'the dead center position to the other on movement of the member between said two positions for efi'ecting a momentary circuit controlling operation of the contacts as the toggle is'mo'ved through the dead center position. r

v 4. A relay'comprising relatively movable cooperating. contacts, a member arranged 'for movement between two positions in either of two opposite directions, means for limiting the movement of said member in each of said directions, electromagnetic means for mov ing the member arranged to exert opposing forces thereon, and contactscontrolling mechanism" arranged to be actuated on movement of the member dueto an "unbalance of the forces exerted thereon for effecting the mo-' 7 mentary closure of the contacts as the member moves in-either direction through an intermediate position; a

5. A relaycomprising relatively movable cooperating contacts, a member. arranged for[ a limited movement in each of two opposite directions, opposing elements respectively tending to move said member in said dii'ections, and contactcontrolling mechanism arranged to be actuated when one of said elements predominates .over the other to move the member for effecting a momentary closure ofthe. contacts as the member moves throu h an intermediate said irections. I

In witness-whereof, I have hereunto 'set my hand this 29thvday of April 1927.

position in either of OLIVERG. TRAVER. 

